Viber is a viable VoIP option, but it trails Skype and Facebook Messenger in important ways.

Every few years, there's a newer, hotter way to communicate with your friends and colleagues. First there was email, then instant messaging, then Skype, then WhatsApp, then Facebook Messenger, and on and on. Viber doesn't add a whole lot to the Skype model, actually lacking several of the bigger player's major features, but it's a well designed and economical way to send text messages and place VoIP calls. The Windows 8.1 Viber app (free) is its latest incarnation, having landed in the last month of 2013. Giving you the same messaging system and ID on your phone, tablet, and PC means Viber is in effect a cross-platform version of iMessage, which is restricted to Apple devices. It doesn't, however, replace Apple FaceTime or Skype's similar video capabilities. Let's take the app for a spin and see how well Viber works at what it can do.

//Compare Similar Products

Installing and Signing Up You get the free Viber app by downloading it from the Windows Store. It works on both Windows 8.1 x86 and Windows RT ARM-based tablets. I tested on both a desktop PC and a Surface RT tablet. Viber apps are available for just about every mobile platform you can think of (and some you can't): iPhone, Android, Windows Phone, Blackberry, Windows, Mac, Symbian, Nokia S40 and Bada.

The first thing you see after installation is the message bar asking you to allow the app access to your webcam and microphone—fair enough, for a communication app. Next, you're asked if you have Viber on your mobile phone. If the answer is No, you're told that you must have the app installed on your smart phone.

Like WhatsApp, Viber is one of those services that require your actual phone number and uses that as your identifier. There are two concerns with this: you're giving out a private personal detail that links to your financial, personal, and contact data to a startup tech company and any Viber contacts can see your real number. It also means you'll have to create a new Viber account if you get a new phone number.

With Kik, Skype, or Facebook Messenger, you simply use your account username, avoiding those pitfalls. On the plus side, the real phone-number approach does make account setup easy, and it means the app can find contacts on the phone. But Skype and the other mobile communication apps I've used can also find your local phone's contacts, so that's not much of a differentiator.

Since Windows 8.1 devices aren't phones, the only way to get going with the Viber app on this platform is to have a cellphone you've installed and activated Viber on. Once that's taken care of, you simply enter your phone number into the Windows 8 app. A "Phone Number Verification" message bar appears, in which you can Edit or OK the entry. The installation process sends a four-digit message to the phone, which you enter in to the Windows 8 app setup. But the permission granting isn't done: you next have to agree to let Viber run in the background.

Interface The Viber app makes good use of many Windows 8-unique features: live tiles, lock screen notifications, pinning specific conversations to the Start screen, the search and share charms. Its main interface even looks a lot like the Windows 8 default People app and like the official Skype app, with tiles representing your contacts, and swiping to take you through the various sections, including Recent, Contacts, and Groups.

It's actually a pleasing, simple, straightforward interface: Just three buttons sit on its right edge: Compose, Keypad, and a Share Viber Facebook button. When you send a message, first a clock icon appears below it, then a double check mark. This change occurred in my testing simply when the receiving phone displayed a lock screen notification with the message, not when the app was actually opened to view the message, so it's a little misleading. Facebook Messenger actually lets you know when the message was "seen."

As I mentioned, you can easily create a Start screen tile for a conversation, but oddly, not for a contact; but that may be more a distinction in terminology than functionality: your ongoing conversation can be with just one contact. One final Windows 8 interface nicety is that when you snap Viber to the side of the screen, it reformats itself conveniently, showing just, for example, the current conversation or rearranging its home screen tile groups vertically.

FeaturesIn a nutshell, Viber offers text messaging and voice-over-IP calling. This means you can save on carrier costs for SMS messages or voice calling minutes. What it doesn't offer is video-calling, like you can get with Skype or Tango.

Text messages with smilies, stickers and photo attachments. I find Viber's stickers more childish and less artistic and cute than the Facebook Messenger stickers, and though you can buy more on other platforms in in-app purchases, the Windows 8 app doesn't support this. You can't send videos in chat, either, as you can in the iPhone version. When you receive a photo, you can easily forward it to another Viber contact. Group text chat, as you'd expect, works just like one-on-one text chat only with multiple participants, but there's no voice group chat like you get in Skype.

My test voice chat in Viber sounded clear and delay-free. Push-to-talk, which the iPhone Viber offers, is not available in the Windows 8 app yet. Placing calls to regular phone numbers using the Viber Out feature comes with reasonable per-minute rates, though you should shop around: Some countries cost less to call through Skype Out, such as Mexico, which Skype only charges 1 cent a minute for compared with Viber's 2.3 cents. For China, it's 1.1 vs 2.3 cents. Unfortunately, the Windows 8 app doesn't seem to offer a way to buy calling credit. On the iPhone, it's a simple matter of an in-app purchase through Apple. Viber's Windows 8 app will trail the other platform versions till in-app purchases are enabled, as we saw previously with stickers.

Transferring a call from your mobile to your tablet or desktop is one of Viber's claims to fame. I was able to transfer a Viber call from an iPhone to the Surface signed into the same account, and it was a one-step tap of the transfer button—no fussing. I could not, however, transfer a Viber Out call (i.e., one to a standard phone line) to the tablet.

Good Viber-ations?Viber offers a viable cross-platform version of iMessage for non-iPhone users, but I prefer Facebook Messenger for that same functionality, since it doesn't require a phone number, has all your Facebook contacts built in, and sports a slicker interface. When it comes to audiovisual features, there's not really much to differentiate Viber from Skype, except for that it offers fewer options—no video calling and no inbound numbers, just to name a couple. And this Windows 8 Viber app doesn't yet support calls to regular phone lines, which you get in Skype. Transferring calls among devices is one plus for Viber, but really, how often do you need to move a call from your mobile to your PC or vice versa? So while Viber is a good service lying somewhere between the messaging-only Kik and WhatsApp on one end and the full video-calling Skype app on the other, the Windows 8 version needs some beefing up before I can highly recommend it.

Michael Muchmore is PC Magazine’s lead analyst for software and Web applications. A native New Yorker, he has at various times headed up PC Magazine’s coverage of Web development, enterprise software, and display technologies. Michael cowrote one of the first overviews of Web Services for a general audience. Before that he worked on PC Magazine’s Solutions section, which covered programming techniques as well as tips on using popular office software. Most recently he covered services and software for ExtremeTech.com.
More »